Characteristics of the gastric mucosa in patients with intestinal metaplasia.

Gastric intestinal metaplasia (IM) occurs in response to different injuries, some of which involve increased risk for gastric cancer, whereas others may not. The background in which IM arises has not been systematically investigated. This study was designed to determine the relative prevalence of the histopathologic conditions of the gastric mucosa associated with IM in a large cohort. We extracted from a database patients who had undergone esophagogastroduodenoscopy with gastric biopsies between January 2008 and December 2013 in endoscopy centers throughout the United States. For each subject we recorded demographic, clinical, and histopathologic information. We stratified patients according to the presence of IM and compared the prevalence of Helicobacter pylori infection, reactive gastropathy, minimal inflammatory and gastropathy changes, mucosal atrophy, gastric polyps, cancer, and lymphoma in the 2 groups. IM, present in 8.4% of the 810,821 unique patients, increased with age and was more common in male than in female individuals. Compared with other Americans, East Asian ancestry was associated with a 5-fold risk for IM. Helicobacter gastritis and its sequelae were present in 42.2% of patients with IM, and reactive gastropathy in 17.3%. In >50% of patients under the age of 30 and in 26% of older adults, foci of IM occurred in an almost normal gastric mucosa. Thus, approximately half of the patients with IM had no histopathologic evidence of current or previous Helicobacter gastritis, whereas almost one fifth had a background of reactive gastropathy. Longitudinal studies are needed to determine the relative risk for gastric cancer in patients with IM associated and not with Helicobacter infection.